This invention relates to a one-piece seat frame structure having a plurality of parallel curvilinear slots which demarcate cantilever-action spring segments.
Seat back assemblies, seat bottom assemblies, and combination seat back-seat bottom assemblies which consist essentially of a seat frame having a plurality of springs, a cushion or pad which rests on the springs, and an upholstery cover are well known in the seating and related arts. Such assemblies are widely used as components of seats for auditoria, theaters, schools and similar public buildings and as components of seats for buses, trains, airplanes and other public transportation vehicles. Of course, such assemblies are used as components of seats for many other public and private use environments.
For the majority of the seat assemblies of the type described above, an open seat frame is manufactured from a suitable structural material, often a wood framing or steel sheet material, and conventional steel springs are positioned across one opening of the frame to support the weight of the occupant of the seat. Typically, the steel springs are of the coiled or serpentine type and are positioned parallel to each other with the opposite ends of each secured to the frame by conventional means, such as engaging holes in the frame with hooks formed on the ends of the springs. Other types of steel springs, such as either bowed or flat slats, and spring fabricated from other materials, such as wood or plastic, are occasionally used with such assemblies.
It is well known to those skilled in the seating and related arts that seat assemblies having a conventional open seat frame with a plurality of conventional springs secured thereto have many inherent disadvantages. For example, conventional steel springs having suitable elastic characteristics add substantially to the cost of manufacturing such assemblies. Furthermore, periodic adjustment and repair is required to maintain the effectiveness of conventional steel springs as flexible or resilient support means. A thick cushion or pad is required to distribute and transfer the seat occupant's weight to the springs and to protect the seat occupant from possible bodily injury by contact with the springs. Upholstering is often a problem when a conventional open seat frame having a plurality of conventional springs is utilized since the springs can tear both the cushion or pad material and the upholstery material.
Various structures have been proposed, and occasionally used, as alternatives for conventional open seat frames having a plurality of conventional springs. For example, U.S. Pat. No. 3,399,883, issued to McKey, for a "Seat Construction", discloses a seat frame structure consisting essentially of a single sheet of resilient material which functions as a flexible or resilient support means for a seat assembly. Two rows of parallel tapered slots permit the midportion of the sheet to assume the contour of the load created by the seat occupant. A similar seat frame structure is disclosed in U.S. Pat. No. 2,804,129, issued to Propst, wherein a single seat of resilient material is provided with parallel untaped slots around its periphery. Each end of each such slot terminates in a circular recess. Unfortunately, neither these structures, nor similar structures which are known in the seating and related arts, have proved to be entirely satisfactory as flexible or resilient support means for seat assemblies inasmuch as they do not efficiently assume the contour of the load created by the seat occupant.
It is desirable to have a one-piece seat frame structure which efficiently assumes the contour of the load created by the seat occupant. Such a seat frame structure, when used as a component of a seat assembly, should be as comfortable for the seat occupant as a conventional open seat frame having a plurality of conventional springs. But, such a seat frame structure should not have the manufacturing cost and other disadvantages which are inherent in conventional structures.